An international treaty, recognising the deleterious effects of ozone depletion is known as

Options

A. Kyoto Protocol
B. Earth Summit
C. Rio Conference
D. Montreal Protocol

Answer

To solve the question regarding the international treaty that recognizes the deleterious effects of ozone depletion, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks for the name of an international treaty that acknowledges the harmful effects of ozone layer depletion.

2. **Analyze the Options**: The options provided are:
- Kyoto Protocol
- Earth Summit
- Rio Conference
- Montreal Protocol

3. **Evaluate Each Option**:
- **Kyoto Protocol**: This treaty focuses on reducing greenhouse gas emissions and is not specifically related to ozone depletion.
- **Earth Summit**: This refers to a series of meetings aimed at sustainable development, not specifically addressing ozone depletion.
- **Rio Conference**: This is another name for the Earth Summit, which also does not specifically target ozone depletion.
- **Montreal Protocol**: This treaty was signed in 1987 and specifically addresses the issue of ozone depletion by controlling substances that harm the ozone layer.

4. **Identify the Correct Answer**: Based on the evaluation, the Montreal Protocol is the treaty that recognizes the harmful effects of ozone depletion and aims to control the emission of ozone-depleting substances.

5. **Conclude**: Therefore, the correct answer to the question is the **Montreal Protocol**.

### Final Answer:
The international treaty recognizing the deleterious effects of ozone depletion is known as the **Montreal Protocol**.

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